reading PDF file with pypdf no contents are captured. Please help

I am trying to read a PDF file using pypdf and write onto a text file. But its not working. content value in the below code is just "u/n/n/n/n/n'...PDF file has 5 pages so 5 times new line character and in the begining 'u'..whats going wrong please help. why the contents are not coming. Any help is highly appreciated. Thanks Sujan